<?xml version="1.0" encoding="utf-8"?>
<!--XBRL document created with Toppan Merrill Bridge  11.4.0.1 -->
<!--Based on XBRL 2.1-->
<!--Created on: 8/13/2026 7:08:29 PM-->
<!--Modified on: 8/13/2026 7:08:29 PM-->
<link:linkbase xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xlink="http://www.w3.org/1999/xlink">
  <roleRef xlink:type="simple" xlink:href="tmc-20260630.xsd#StatementCondensedConsolidatedBalanceSheets" roleURI="http://tmc.com/role/StatementCondensedConsolidatedBalanceSheets" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="tmc-20260630.xsd#StatementCondensedConsolidatedStatementsOfLossAndComprehensiveLoss" roleURI="http://tmc.com/role/StatementCondensedConsolidatedStatementsOfLossAndComprehensiveLoss" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="tmc-20260630.xsd#StatementCondensedConsolidatedStatementsOfCashFlows" roleURI="http://tmc.com/role/StatementCondensedConsolidatedStatementsOfCashFlows" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="tmc-20260630.xsd#DisclosureExplorationAndEvaluationExpensesDetails" roleURI="http://tmc.com/role/DisclosureExplorationAndEvaluationExpensesDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="tmc-20260630.xsd#DisclosureGeneralAndAdministrativeExpensesDetails" roleURI="http://tmc.com/role/DisclosureGeneralAndAdministrativeExpensesDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="tmc-20260630.xsd#DisclosureAccountsPayableAndAccruedLiabilitiesDetails" roleURI="http://tmc.com/role/DisclosureAccountsPayableAndAccruedLiabilitiesDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="tmc-20260630.xsd#DisclosureFinancialInstrumentsScheduleOfCategoriesOfFinancialInstrumentsDetails" roleURI="http://tmc.com/role/DisclosureFinancialInstrumentsScheduleOfCategoriesOfFinancialInstrumentsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <link:arcroleRef arcroleURI="https://xbrl.org/2023/arcrole/summation-item" xlink:type="simple" xlink:href="https://www.xbrl.org/2023/calculation-1.1.xsd#summation-item" />
  <calculationLink xlink:role="http://tmc.com/role/StatementCondensedConsolidatedBalanceSheets" xlink:type="extended" xlink:title="995200100 - Statement - Condensed Consolidated Balance Sheets" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets_1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Assets_1" xlink:to="us-gaap_AssetsCurrent_639222449052171127" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_639222449052171127" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_639222449052171127" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_ReceivablesAndPrepaymentsCurrent" xlink:label="tmc_ReceivablesAndPrepaymentsCurrent_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_639222449052171127" xlink:to="tmc_ReceivablesAndPrepaymentsCurrent_639222449052171127" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsNoncurrent" xlink:label="us-gaap_AssetsNoncurrent_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Assets_1" xlink:to="us-gaap_AssetsNoncurrent_639222449052171127" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_ExplorationLicensesNoncurrent" xlink:label="tmc_ExplorationLicensesNoncurrent_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsNoncurrent_639222449052171127" xlink:to="tmc_ExplorationLicensesNoncurrent_639222449052171127" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsNoncurrent_639222449052171127" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset_639222449052171127" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsNoncurrent_639222449052171127" xlink:to="us-gaap_PropertyPlantAndEquipmentNet_639222449052171127" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsNoncurrent_639222449052171127" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill_639222449052171127" order="4" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermInvestments" xlink:label="us-gaap_LongTermInvestments_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsNoncurrent_639222449052171127" xlink:to="us-gaap_LongTermInvestments_639222449052171127" order="5" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_Liabilities_639222449052171127" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Liabilities_639222449052171127" xlink:to="us-gaap_LiabilitiesCurrent_639222449052171127" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent_639222449052171127" xlink:to="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_639222449052171127" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilitiesCurrent" xlink:label="us-gaap_DerivativeLiabilitiesCurrent_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent_639222449052171127" xlink:to="us-gaap_DerivativeLiabilitiesCurrent_639222449052171127" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesNoncurrent" xlink:label="us-gaap_LiabilitiesNoncurrent_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Liabilities_639222449052171127" xlink:to="us-gaap_LiabilitiesNoncurrent_639222449052171127" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:label="us-gaap_DeferredIncomeTaxLiabilitiesNet_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesNoncurrent_639222449052171127" xlink:to="us-gaap_DeferredIncomeTaxLiabilitiesNet_639222449052171127" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_AccruedRoyaltiesNonCurrent" xlink:label="tmc_AccruedRoyaltiesNonCurrent_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesNoncurrent_639222449052171127" xlink:to="tmc_AccruedRoyaltiesNonCurrent_639222449052171127" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_StockholdersEquity_639222449052171127" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_639222449052171127" xlink:to="us-gaap_CommonStockValue_639222449052171127" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_639222449052171127" xlink:to="us-gaap_AdditionalPaidInCapital_639222449052171127" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_639222449052171127" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_639222449052171127" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_639222449052171127" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_639222449052171127" order="4" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://tmc.com/role/StatementCondensedConsolidatedStatementsOfLossAndComprehensiveLoss" xlink:type="extended" xlink:title="995200200 - Statement - Condensed Consolidated Statements of Loss and Comprehensive Loss" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_IncomeTaxExpenseBenefit_639222449052171127" order="1" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_639222449052171127" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_FeesAndInterestOnCreditFacility" xlink:label="tmc_FeesAndInterestOnCreditFacility_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_639222449052171127" xlink:to="tmc_FeesAndInterestOnCreditFacility_639222449052171127" order="1" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_GainLossOnRemeasurementOfEquitySettledObligation" xlink:label="tmc_GainLossOnRemeasurementOfEquitySettledObligation_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_639222449052171127" xlink:to="tmc_GainLossOnRemeasurementOfEquitySettledObligation_639222449052171127" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeExpenseNet" xlink:label="us-gaap_InterestIncomeExpenseNet_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_639222449052171127" xlink:to="us-gaap_InterestIncomeExpenseNet_639222449052171127" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:label="us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_639222449052171127" xlink:to="us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_639222449052171127" order="4" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAdjustmentOfWarrants" xlink:label="us-gaap_FairValueAdjustmentOfWarrants_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_639222449052171127" xlink:to="us-gaap_FairValueAdjustmentOfWarrants_639222449052171127" order="5" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_GainLossOnDilutionOfInvestments" xlink:label="tmc_GainLossOnDilutionOfInvestments_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_639222449052171127" xlink:to="tmc_GainLossOnDilutionOfInvestments_639222449052171127" order="6" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal" xlink:label="us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_639222449052171127" xlink:to="us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_639222449052171127" order="7" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_WarrantsIssuanceCosts" xlink:label="tmc_WarrantsIssuanceCosts_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_639222449052171127" xlink:to="tmc_WarrantsIssuanceCosts_639222449052171127" order="8" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_639222449052171127" xlink:to="us-gaap_OperatingIncomeLoss_639222449052171127" order="9" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="us-gaap_GeneralAndAdministrativeExpense_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_OperatingIncomeLoss_639222449052171127" xlink:to="us-gaap_GeneralAndAdministrativeExpense_639222449052171127" order="1" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ExplorationExpense" xlink:label="us-gaap_ExplorationExpense_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_OperatingIncomeLoss_639222449052171127" xlink:to="us-gaap_ExplorationExpense_639222449052171127" order="2" use="optional" weight="-1" />
  </calculationLink>
  <calculationLink xlink:role="http://tmc.com/role/StatementCondensedConsolidatedStatementsOfCashFlows" xlink:type="extended" xlink:title="995200400 - Statement - Condensed Consolidated Statements of Cash Flows" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:label="CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" xlink:to="us-gaap_ComprehensiveIncomeNetOfTax_639222449052171127" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_WarrantsIssuanceCosts" xlink:label="tmc_WarrantsIssuanceCosts_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" xlink:to="tmc_WarrantsIssuanceCosts_639222449052171127" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentForAmortization" xlink:label="us-gaap_AdjustmentForAmortization_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" xlink:to="us-gaap_AdjustmentForAmortization_639222449052171127" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseExpense" xlink:label="us-gaap_OperatingLeaseExpense_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" xlink:to="us-gaap_OperatingLeaseExpense_639222449052171127" order="4" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_SettlementOfObligationThroughShareIssuance" xlink:label="tmc_SettlementOfObligationThroughShareIssuance_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" xlink:to="tmc_SettlementOfObligationThroughShareIssuance_639222449052171127" order="5" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseDebt" xlink:label="us-gaap_InterestExpenseDebt_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" xlink:to="us-gaap_InterestExpenseDebt_639222449052171127" order="6" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal" xlink:label="us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" xlink:to="us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_639222449052171127" order="7" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" xlink:to="us-gaap_ShareBasedCompensation_639222449052171127" order="8" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_GainLossOnDilutionOfInvestments" xlink:label="tmc_GainLossOnDilutionOfInvestments_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" xlink:to="tmc_GainLossOnDilutionOfInvestments_639222449052171127" order="9" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAdjustmentOfWarrants" xlink:label="us-gaap_FairValueAdjustmentOfWarrants_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" xlink:to="us-gaap_FairValueAdjustmentOfWarrants_639222449052171127" order="10" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_InterestPaidOnShortTermBorrowings" xlink:label="tmc_InterestPaidOnShortTermBorrowings_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" xlink:to="tmc_InterestPaidOnShortTermBorrowings_639222449052171127" order="11" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyTransactionGainLossUnrealized" xlink:label="us-gaap_ForeignCurrencyTransactionGainLossUnrealized_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" xlink:to="us-gaap_ForeignCurrencyTransactionGainLossUnrealized_639222449052171127" order="12" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_639222449052171127" order="13" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_IncreaseDecreaseInReceivablesAndPrepaidExpense" xlink:label="tmc_IncreaseDecreaseInReceivablesAndPrepaidExpense_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" xlink:to="tmc_IncreaseDecreaseInReceivablesAndPrepaidExpense_639222449052171127" order="14" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_GainLossOnRemeasurementOfEquitySettledObligation" xlink:label="tmc_GainLossOnRemeasurementOfEquitySettledObligation_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_639222449052171127" xlink:to="tmc_GainLossOnRemeasurementOfEquitySettledObligation_639222449052171127" order="15" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_639222449052171127" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities_639222449052171127" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_639222449052171127" order="1" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital" xlink:label="us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities_639222449052171127" xlink:to="us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital_639222449052171127" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireEquityMethodInvestments" xlink:label="us-gaap_PaymentsToAcquireEquityMethodInvestments_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities_639222449052171127" xlink:to="us-gaap_PaymentsToAcquireEquityMethodInvestments_639222449052171127" order="3" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_639222449052171127" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_ProceedsFromIssuanceRegisteredDirectOffering" xlink:label="tmc_ProceedsFromIssuanceRegisteredDirectOffering_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_639222449052171127" xlink:to="tmc_ProceedsFromIssuanceRegisteredDirectOffering_639222449052171127" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_639222449052171127" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock_639222449052171127" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_PaymentsOfStockIssuanceCostsRegisteredDirectOffering" xlink:label="tmc_PaymentsOfStockIssuanceCostsRegisteredDirectOffering_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_639222449052171127" xlink:to="tmc_PaymentsOfStockIssuanceCostsRegisteredDirectOffering_639222449052171127" order="3" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="us-gaap_ProceedsFromStockOptionsExercised_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_639222449052171127" xlink:to="us-gaap_ProceedsFromStockOptionsExercised_639222449052171127" order="4" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_RepaymentOfWorkingCapitalLoan" xlink:label="tmc_RepaymentOfWorkingCapitalLoan_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_639222449052171127" xlink:to="tmc_RepaymentOfWorkingCapitalLoan_639222449052171127" order="5" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfLinesOfCredit" xlink:label="us-gaap_RepaymentsOfLinesOfCredit_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_639222449052171127" xlink:to="us-gaap_RepaymentsOfLinesOfCredit_639222449052171127" order="6" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromWarrantExercises" xlink:label="us-gaap_ProceedsFromWarrantExercises_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_639222449052171127" xlink:to="us-gaap_ProceedsFromWarrantExercises_639222449052171127" order="7" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfPrivatePlacement" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_639222449052171127" xlink:to="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_639222449052171127" order="8" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromStockPlans" xlink:label="us-gaap_ProceedsFromStockPlans_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_639222449052171127" xlink:to="us-gaap_ProceedsFromStockPlans_639222449052171127" order="9" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://tmc.com/role/DisclosureExplorationAndEvaluationExpensesDetails" xlink:type="extended" xlink:title="99940901 - Disclosure - Exploration and Evaluation Expenses (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ExplorationExpense" xlink:label="us-gaap_ExplorationExpense" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_EnvironmentalStudies" xlink:label="tmc_EnvironmentalStudies_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_ExplorationExpense" xlink:to="tmc_EnvironmentalStudies_639222449052171127" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_ExplorationLabor" xlink:label="tmc_ExplorationLabor_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_ExplorationExpense" xlink:to="tmc_ExplorationLabor_639222449052171127" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_CommonSharesOptionsBasedPayments" xlink:label="tmc_CommonSharesOptionsBasedPayments_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_ExplorationExpense" xlink:to="tmc_CommonSharesOptionsBasedPayments_639222449052171127" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_MiningTechnologicalAndProcessDevelopment" xlink:label="tmc_MiningTechnologicalAndProcessDevelopment_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_ExplorationExpense" xlink:to="tmc_MiningTechnologicalAndProcessDevelopment_639222449052171127" order="4" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_PrefeasibilityStudies" xlink:label="tmc_PrefeasibilityStudies_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_ExplorationExpense" xlink:to="tmc_PrefeasibilityStudies_639222449052171127" order="5" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_SponsorshipTrainingAndStakeholderEngagement" xlink:label="tmc_SponsorshipTrainingAndStakeholderEngagement_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_ExplorationExpense" xlink:to="tmc_SponsorshipTrainingAndStakeholderEngagement_639222449052171127" order="6" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_OtherExplorationAndEvaluationExpenses" xlink:label="tmc_OtherExplorationAndEvaluationExpenses_639222449052171127" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_ExplorationExpense" xlink:to="tmc_OtherExplorationAndEvaluationExpenses_639222449052171127" order="7" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://tmc.com/role/DisclosureGeneralAndAdministrativeExpensesDetails" xlink:type="extended" xlink:title="99941001 - Disclosure - General and Administrative Expenses (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="us-gaap_GeneralAndAdministrativeExpense_1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfessionalFees" xlink:label="us-gaap_ProfessionalFees_639222449052291985" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_GeneralAndAdministrativeExpense_1" xlink:to="us-gaap_ProfessionalFees_639222449052291985" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_InvestorRelationsExpense" xlink:label="tmc_InvestorRelationsExpense_639222449052291985" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_GeneralAndAdministrativeExpense_1" xlink:to="tmc_InvestorRelationsExpense_639222449052291985" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_OfficeAndSundryExpenses" xlink:label="tmc_OfficeAndSundryExpenses_639222449052293726" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_GeneralAndAdministrativeExpense_1" xlink:to="tmc_OfficeAndSundryExpenses_639222449052293726" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LaborAndRelatedExpense" xlink:label="us-gaap_LaborAndRelatedExpense_639222449052293726" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_GeneralAndAdministrativeExpense_1" xlink:to="us-gaap_LaborAndRelatedExpense_639222449052293726" order="4" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestExpenseDirectorsFees" xlink:label="us-gaap_NoninterestExpenseDirectorsFees_639222449052293726" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_GeneralAndAdministrativeExpense_1" xlink:to="us-gaap_NoninterestExpenseDirectorsFees_639222449052293726" order="5" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_639222449052293726" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_GeneralAndAdministrativeExpense_1" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense_639222449052293726" order="6" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestExpenseTransferAgentAndCustodianFees" xlink:label="us-gaap_NoninterestExpenseTransferAgentAndCustodianFees_639222449052293726" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_GeneralAndAdministrativeExpense_1" xlink:to="us-gaap_NoninterestExpenseTransferAgentAndCustodianFees_639222449052293726" order="7" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_TravelAndOtherExpenses" xlink:label="tmc_TravelAndOtherExpenses_639222449052299335" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_GeneralAndAdministrativeExpense_1" xlink:to="tmc_TravelAndOtherExpenses_639222449052299335" order="8" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://tmc.com/role/DisclosureAccountsPayableAndAccruedLiabilitiesDetails" xlink:type="extended" xlink:title="99941101 - Disclosure - Accounts Payable and Accrued Liabilities (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrent_639222449052299335" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:to="us-gaap_AccruedLiabilitiesCurrent_639222449052299335" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableCurrent" xlink:label="us-gaap_AccountsPayableCurrent_639222449052299335" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:to="us-gaap_AccountsPayableCurrent_639222449052299335" order="2" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://tmc.com/role/DisclosureFinancialInstrumentsScheduleOfCategoriesOfFinancialInstrumentsDetails" xlink:type="extended" xlink:title="99941501 - Disclosure - Financial Instruments - Schedule of categories of financial instruments (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_FinancialAssets" xlink:label="FinancialAssets" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_639222449052299335" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="FinancialAssets" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_639222449052299335" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_TaxesAndOtherReceivablesCurrent" xlink:label="tmc_TaxesAndOtherReceivablesCurrent_639222449052299335" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="FinancialAssets" xlink:to="tmc_TaxesAndOtherReceivablesCurrent_639222449052299335" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_FinancialLiabilities" xlink:label="FinancialLiabilities" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_AccruedRoyaltiesNonCurrent" xlink:label="tmc_AccruedRoyaltiesNonCurrent_639222449052299335" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="FinancialLiabilities" xlink:to="tmc_AccruedRoyaltiesNonCurrent_639222449052299335" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="tmc-20260630.xsd#tmc_WarrantLiability" xlink:label="tmc_WarrantLiability_639222449052299335" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="FinancialLiabilities" xlink:to="tmc_WarrantLiability_639222449052299335" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_639222449052299335" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="FinancialLiabilities" xlink:to="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_639222449052299335" order="3" use="optional" weight="1" />
  </calculationLink>
</link:linkbase>
